This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study is looking at cerebrospinal fluid and brain imaging in patients with dementia. Based on previous observations, the investigators believe that certain enzymes will be present in patients for whom vascular injury contributes to or causes their dementia.